Tool spindle with removable projection



Filed Sept. ll. 1941 E. S. CORNELL ETAL TOOL SPINDLE WITH REMOVABL-EPROJECTION Sept. 28, 1943.

Patented Sept. Z8, 1943 T OFFICE t "root SPINDLE; WITH REMOVABLE IrRoJEC'rroN f Elma s. comen, Charlestown, N. and charles AN. ,WilliamaSpringeld,. Vt, assignors t` Bryant Chucking vGrinder Company,Springlfield, Vt., a corporation of Vermont Application September 11,1941, Serial No. 410,424 i io claims. Y (o1. 287-125) It is oftendesirable to removably attach projections coaxial with rotary spindles,jas, 'forexample, when it is desired -to use different rotary tools foroperating on work without requiring resetting or rechucking of the Work,a tool beingY carried by each projection and the projections beinginterchanged as desired, or forveconomy to avoid the necessity of usingindividual separate spindles for each tool to be employed. It :is im.

portantV that' sucha projection shall be accurately coaxial with thespindle towhichit is applied, and that it shall be readily removable forreplacement by other projections. Where-intertting conical partsV on thespindle and pro-V jection have been employed, if the taper. is made longin an effort to obtain accurate concentricity, there is danger of theparts becoming 'so firmly united as to make separation extremelydiicult. Attempts to remove the projection might then cause damage tothe parts.' This isi particularly likely to happen if a coldprojectionbe inserted into a hot spindle. tion warms up and expands, it `stickstightly in the spindle and as the temperatures of the spindle andprojection while they are in mutual contact remain fairly closetogether,` `the `parts thereafter remain ,tightly xed. It'zis .seldompossible to provide a hole through the spindle for the passage of anejector. rod for engagement and removal of the projection, andwhenprovide'd it adds to the expense of the structure and may create toomuch unbalance for high speed spin dles. If a relatively steep vtaper`between the spindle and projection is employed toavoid undue sticking,the projection is more easily influ- I enced by stresses suchforexample, as from interengaging threaded portionson the spindle andprojection for retaining purposes, so as to become misalined `with thespindle. Threaded connections between the spindle and the projecetionfof themselves do not afford the required accuracy of coaxial alinement,and the engage-r yment of these threads may irnpcse lateral forcestending further to prevent coaxial alinement of' tion coaxial to thespindlaland of sufficiently As the projec-` To this end steep taper toavoid undue-sticking, together with a threaded connection between theseparts located betweeny the tapered portions and soarranged as to causepositive axial relative motion of the parts on* relative rotationthereof but without causing side thrusts tending to throw the parts outof proper alinement.

For a more complete understanding of this invention, reference may behad to"the accompanying drawing in which Figure 1 is'a fragmentary Viewpartly brokenaway and'in section of a spindle projection and withcooperating `parts of the spindle and its mounting, the Vprojectionbeing shown withdrawn from the spindle.

`Figure 2 is afragmentary view to a larger s'cale'of the cooperatingparts' ofthe spindle and projection and showing these parts inassembledrelation. y v i Referring to the drawing, at l is indicated aspindle which is shown `as supported for rotation in ball-bearings 2froma supporting frame member 3; Asshown this spindle is intended forsupporting a rotary grinding Wheel and in order to prevent grit andother foreign I vmatter from reaching the bearings 2,V sealing memberscomprising an annular sealing member 4 carried byy the casing Sand anannular sealing member 5 carried by a reduced 'diameterend portion 6 ofthe spindle have been illustrated.` These :ing

yportions 4 and 5 are arranged closely together but out of contact witheach other and the mem-l ber 5 may have'an annular n 'l which extendsinto an annular groove 8 of the member 4. The member 4 may also`beprovided with an internal groove 9; This arrangement effectively sealsoff the passage of foreign matter from outside the spindle intothebearings and at the same time permits free rotation of the spindle.The meinber 5 is shown as threaded for engagement with external threadsin the portion 6 of the spindle and the annular member 4`is shown lalsoas threaded into the internally threaded portion I0 of the casing 3.

The outerend of the spindle I is provided with asocket I2 within whichmay be extended the portion I3 of theprojection I4 which is shown inFigure 1 as supporting a grinding wheel I5 atlits outer end. This socketI2 has a pair of axially spaced tapered internal faces l5 and I 'I andthe portion I3 has matingly tapered axially spaced external surfaces I8and I9. The angle of taper of the internal faces I6 and I'I` ofthespindle andthe external faces iS and`|9 of the projection is sufcientlysteep so that the projection is not liable to become too firmly wedgedinto the spindle socket I2 to prevent removal. For ground steel surfacesan angle of approximately 18 will usually be found satisfactory.Preferably, particularly for the purpose of providing for easy machiningof the parts, the faces I6 and I'I 'and the faceswl and I9,respectively, are arranged as portions of the same conical surface andthe' parts between the surfaces I6 and I'I are arranged at least asremote from the central axis as this cone surface.v This permits thesesurfaces I6 and II to be taper ground in a grinding machine withoutrequiring relative Y dle and rotation in the opposite direction servingvio to move these faces relatively into close controlengagementaccurately locating the projec- -tionjin axial alinement with thespindle.

adjustments of the grinding Wheel and gthe worksf' in the wheel grindingstrokes for finishing these For grinding the .ex-.. ternal surfaces I8and I 9 it is only necessary when axially spaced surfaces.

using a single wheel to provide .a cut away por.- tion intermediate itslength to clear the inter- This intermediate substantially coaxial`cylin- The tapered bearing surfaces at opposite ends of the threadedengagement tend to produce high ac- ;curacyof .coaxial alinement betweenthe projec- 1 .tion andspindle.'

drical portion 2l] between the externally tapered y surfaces I8 and I9of the projection :is extern-ally threaded to matean internally threadednonta-pering substantially coaxial `portion 2i of the socket I2 in thespindle. Preferably in order `that the engagement of these threadedportions-shall exert no .undesirable side thrusts between `the spindleand projection, thus to avoid tendency vto force the projection out -oftrue axial yal-inement with the spindle, the working side faces ofthemating'threads are steep Aas illustrated best'in Figure 2 so as toproduce by their engagement as small a lateral component of pressureasis practicable. They are shown las vertical fon the tightening orworking side so :that there is .no lateral .pressure component. -If assteep as the angle of repose, when they are brought intox-.contact-nosubstantial lateral forces tending'to distort-the parts or throw themout vvof ytrue I,axial alinement will be exerted. ALikewiseinorder-.that the thrust exerted between these -fthreaded portions shall`be axial, -t-heyare formed non-center,- ing so that they may iioatrelatively as :shown in Figure 2 upto the point where .their confrontingsteep faces tightly engage, the centering 'reffect being accomplishedentirely by the tapered faces of the spindle socketandtheprojection'xand the threads of `thetvvo `parts lbeing out toffcontaclt with each other` except at said steepfaces. Where the angle ofthe thread .faces is ,thus .steep.:any centering tendency'asthethread-:faces come togetheigj'is overcome -by the Y.frictiontherebetween which prevents actual relative-.sliding motion vhetween thetwo -parts laterally of :the axis. The

- term steep side face `as applied to .thefthreads and as used herein isdefinedasza'side facezwhich departs fromperpendicular yto *the axis :o'f:athe

piece :by .not substantially more :than the L angle f StandardsvCommittee and ;is wit-hin theiangle of.A

repose'. :Preferably zthe #socket portion I2 .is 'enlarged somewhat 'in:certain Yaxial Zones zto `gorovide the clearance spaces A22 and .23.shown best in Figure 2, thus to further fprovide ffor =-the escape ofany Iforeign. matter which otherwise might tend -to @prevent gproper-.contact between the tapered surfaces-of the.spindle andprcjec- Fromthe foregoing description of an embodiment of this'invention, it shouldbe evident to those skilled in the art that various modications andChanges might be made without departing from the spirit or scope of thisinvention.

Weclaim:

41. -In combination, a spindle and .a removable projection .for saidspindle, said spindle and-projection .having a ,pair Yof axially spacedcooperating 'tapered portions for locating said projection coaxial with'said spindle, and interengaging cylindrical threaded .portions of saidspindle `and projection located lbetween said pairs lof taperedpor-tions forsecuring Asaid projection to said spindie, saidthreadedportions having steep engaging yside `faces.

2.I-n combination, -a spindle and a removable projection .for ,saidspindle, said spindle and projection having .apair of axially spacedcooperating Itfn'iered vportions `for ,locating .said projection coaxialwith said spindle, and interengaging cylindrica'l threaded `portions ofsaid spindle .and projection located between said pairs of taperedportions for/securing said `projection to said spindle,.:said pairs oftapered .portions lying in the same 'conical isurface.,fsaid threaded.portionszhaving vsteep engaging :side faces.

3. In combination, fa spindle and a .removable proiectionfor Isaidspindle, .said spindle .and projection having .a pair of axially spacedcooperating tapered portions for locating said projection coaxial ywithf said spindle, .and .interengaging cylindrical-threaded portions `ofsaid spindle and projection .located betweensaid vpairs of :taperedportions forsecuning-saidprojection to said spindie, 'said threadedvportions having steep engaging side V.faces :and being .in,non-centering relation toeach other.

In combination, :a lspindle and .a removable projection for :saidspindle, said spindle and projection having :a pair :of axially vspaced.cooperatngatapered portions forlocating said .projection coaxial withsai-d spindle, and interengaging-'cylindrical `threaded portions of.sai-d spindle and projection located lbetween .said pairs of taperedportions for securing said projection'tosaid spindle., said pairs .oftapered zportions Kl-ying :in .the same 'conical rsur'fa'ce,saidxthreaded portions lvhavj ing steep engagingside faces and beingin..non

centering relation to-geachgother.

. 5. -A spindle projection fhaving :a pair of .axiallyspaoed -COnCalpilot fportions with :their sur.-

- faces .forming 4parts Lof .the same cone, and a substantially-.eoaxialexternally threaded cylindrical part Ebetween .-said -portions having:steep active thread faces.-

I6. A spindle 'having a coaxial'socket in one end, said .socket havingTa pair Tof axiallyspaced :conical A,wall portions, and an internallythreaded .cy-

` lindrical portion '1n the space between said coni'- said socket havinga pair of axially spaced conical wall portions,'and an internallythreaded substantially coaxia1 cylindrical portion in the space betweensaid conical wall portions and having steep thread faces, saidconicalwall portions being portions of a single conical surface.

8. A spindle having a coaxial socket in one end, said socket having apair of axially spaced conical wall portions, and an internally` steepthreaded substantially coaxial cylindrical portion in the space betweensaid conical wall portions, said conical wall portions being portions ofa single conical surface and no portion of said nontapering portionextending inwardly of said single conical surface.

9. A spindle having a coaxial socket in one end,

said socket having a pair of axially spaced coni- 20 cal wall portions,andan internally threaded portion in the space between said conical wallAportions, said conical wall portions being portions of a single conicalsurface, said socket having clearance spaces between said threaded andconical wall portions of larger diameter than the corresponding parts ofthe single conical surface.

10. A spindle having a coaxia1 socket in one end, said socket having apair of axially spaced concentric conical wall portions, and anextension having a pair of axially spaced concentric external conicalvsurfaces mating the wall portions of said socket, said socket andextension having mating cylindrical threaded portions be.- tween theirrespective conical portions and conical surfaces, said threaded portionslying in radial non-centering relation and having steep workingcomplemental faces.

ELTON S CORNELL.

CHARLES N. WILLIAMS.

